Guys have been responding to this question for five years! It's an interesting one. Watch a porn movie and it's difficult, for a guy who has never sucked cock and doesn't want to, to believe that anyone could enjoy doing it. Why would any guy let another stick a cock down his throat, make him retch, gasp, struggle for breath...? And yet we go on getting down on our knees, opening our mouths and throats, and begging to be used.
There's a guy I meet up with from time to time. 6ft 3in - black - American - 50s - big build - big cock. He likes having his cock sucked - and not much else. He's complicated, angry (about black history in the USA), vulnerable. I love sucking his cock because.... it's about trying to make him feel good, to soothe him.... normally I find opening my throat to a big cock a challenge, but with him it seems to happen naturally, it's not a challenge... I feel replete afterwards, even if he hasn't cum, and I haven't (I never do when I'm with him).... He lets me lie beside him afterwards and hold him, and he mostly goes to sleep in my arms for a while (which feels beautiful)....
So it's about making love - to the outsider the way people make love can seem weird - but, if you care about someone, you do - and delight in doing - whatever makes them happy.